Setup docker compose

This is required for this version of Sassc on M1 Macs:
sass/sassc-ruby#218

.env

@@ -0,0 +1 @@
+COMPOSE_FILE=docker-compose.yml:docker-compose-dev.yml

README.md

@@ -31,3 +31,19 @@ bundle exec jekyll serve --livereload
 ```
 
 Preview the site at http://127.0.0.1:4000.
+
+
+## Local Docker Usage
+
+Install Dependencies:
+
+```
+docker compose run script bundle install
+```
+
+
+Run the Jekyll server:
+
+```
+docker compose up
+```

docker-compose-dev.yml

@@ -0,0 +1,10 @@
+version: "3"
+
+services:
+  app:
+    volumes: [ bundle:/usr/local/bundle ]
+  script:
+    volumes: [ bundle:/usr/local/bundle ]
+
+volumes:
+  bundle:

docker-compose.yml

@@ -0,0 +1,21 @@
+version: "3"
+
+services:
+  app:
+    image: ruby:2.7
+    working_dir: /work
+    volumes: [ ".:/work" ]
+    command: "bundle exec jekyll serve --livereload --host=0.0.0.0"
+    ports: [ "4000:4000" ]
+  script:
+    image: ruby:2.7
+    working_dir: /work
+    volumes: [ ".:/work" ]
+    stop_signal: SIGKILL
+    command:
+      - bash
+      - -c
+      - |
+        echo "
+        To execute a script, run:
+        docker-compose run script {command}"